Development Of PMSM Drive System And Energy Feedback System For Oil Field Application

This paper developed a PMSM drive system for long stroke pumping unit in oil field application.And the conventionally used brake resistor was replaced by an energy feedback unit to save energy.In terms of the PMSM driver,by comparing typical control methods in oil field context,a design using Field Oriented Control(FOC)and resolver angle detector was adapted.Then main functions in the system were discussed,like the design of angle measurement function and the calibrating scheme of resolver.Software simulation was used to verify the design.In terms of the energy feedback unit,this system was implemented with a parallel 3-phase grid connected inverter.The inverter’s characteristic was analyzed with mathematical modeling.And then key techniques like PLL and stator current control techniques were discussed.Then the designing of control system and hardware parameters were conducted.The design was verified with software simulation.In addition,problems in paralleling the PMSM driver and the energy feedback unit were discussed,like power circuits and circulating current problems.This paper analyzed the mechanism of these problems and proposed solutions.The performance of the solution was verified with software simulation.The performance of the system was finally verified by being tested in real oil field context.And the performance met the requirement of the oil field application.And the practicability of the design was proved.